1. Field of the Invention
This invention relates to a method of producing anesthesia in a mammal using ketazocine.
2. Description of the Prior Art
U.S. Pat. No. 3,936,462, issued Feb. 3, 1976, describes racemic ketazocine (1,2,3,4,5,6-hexahydro-1-oxo-3-cyclopropylmethyl-9[sic, should read 8]-hydroxy-6(eq),11(ax)-dimethyl-2,6-methano-3-benzazocine) having the structural formula ##STR1## in Example 1 and dextro- and levo-ketazocine in Example 51 and salts thereof. Ketazocine and the other disclosed benzomorphans are described as "analgesic antagonists and analgesics". The patent does not describe or suggest the anesthetic use of ketazocine or any of the other disclosed benzomorphans, nor is any other prior description or suggestion of such use known to applicant.
General anesthetics depress the central nervous system and induce varying degrees of analgesia, depression of consciousness, skeletal muscle relaxation, and reduced reflex activity. The ideal general anesthetic should be stable, nonflammable, prompt acting, metabolically inert, and rapidly eliminated. It should provide adequate analgesia and muscular relaxation without producing excitement or any adverse effects on vital organs and systems, even during prolonged administration. Recovery of consciousness should occur quickly with no adverse after-effects or complications. No single agent presently available possesses all of these ideal characteristics [AMA Drug Evaluations, Third Edition, Publishing Sciences Group, Inc., Littleton, Mass., 1977, p. 285].
The general anesthetics are classified as inhalation anesthetics and intravenous anesthetics (ibid., chap. 18, pp. 285-299). Adjuncts to anesthesia, which are not themselves anesthetics, (ibid., chap. 19, pp. 300-324) including diazepam (ibid., p. 302) are frequently used with the general anesthetics. The commonly used intravenous anesthetics are the barbiturates, for example, thiopental sodium, and a nonbarbiturate, ketamine hydrochloride, which are seldom used alone but are generally used in combination with the inhalation anesthetics. Moreover, the barbiturates have little if any analgesic activity and ketamine hydrochloride has undesirable cerebrospinal fluid pressor, central nervous system excitatory, and hallucinatory and other psychic effects. There is therefore a need for an intravenous anesthetic which is self-sufficient as an anesthetic, which has good analgesic properties unlike the barbiturates and which does not have the undesirable effects of ketamine hydrochloride.